1. Field of the Invention
The present invention relates to a system and method for aligning an automated robotic device in a data storage library.
2. Background
In the past, non-contacting position detection systems for use in automated tape storage libraries have used video camera systems for aligning a robot to select and remove magnetic tape cartridges stored within the library. For the robot to remove the tape cartridges, the robot must include some type of retrieval mechanism for securing the tape cartridges. For best performance, it is desirable to closely align the retrieval mechanism with the tape cartridges. Video camera systems can assist in aligning the robot by detecting indicia on or around the tape cartridge. The video system scans the indicia and determines a relationship of the indicia to the robot for alignment of the robot with the tape cartridge.
The video camera system usually includes a predetermined arrangement for the indicia. As described in U.S. Pat. No. 5,303,034, one such arrangement can be an xe2x80x9cN-typexe2x80x9d target. The video camera system scans the indicia to record a number of pixels which represent an image of the xe2x80x9cN-typexe2x80x9d target used for determining the center of the target.
In addition to using the robot for selecting and removing tape cartridges, the robot can also include a barcode scanner for reading information stored on a barcode label affixed to the tape cartridge. Consequently, the robot may include both video camera and barcode scanning systems.
As barcode scanning systems are smaller and less expensive than video camera systems, it would be desirable to provide a target which can be read by a barcode scanner, or similar system so that the robot would only need one system for reading the barcode labels affixed to the tape cartridges and the indicia on the targets affixed within the storage library system for use in aligning the robot. Moreover, it would be desirable to provide a scanning system for use in aligning the robot that is an improvement over existing video camera alignment systems.
In the future, memory in cartridge (MIC) systems will be used for collecting the information that was once read from a barcode. MIC systems utilize radio frequency (RF) technology to communicate the barcode information, instead of scanning the barcode. Accordingly, it would be desirable for the robot to include a scanning system for assistance with aligning the robot and a MIC system for collecting the RF information from the tape cartridge.
Accordingly, the present invention relates to a system for use in a data storage library having a plurality of cells for housing media cartridges, each cell having a location in the library, the library further having a moveable robot including for use in retrieving the cartridges from the cells. The system comprises a target in the library. The target has a first target portion with a first reflectivity, a second target portion with a second reflectivity, and a third target portion with a third reflectivity. In addition, the system comprises a source on the robot for directing a beam toward the target and an actuator for use in scanning the beam source over the first, second and third target portions. The beam reflects off the target portions as a reflected beam having an intensity based on the reflectivity of the respective target portion. Furthermore, the system comprises a sensor on the robot for sensing the reflected beam and generating a signal representing the intensity of the reflected beam. Finally, the system comprises a controller for receiving the signal from the sensor. The controller determines a location of the target in the library relative to the robot based on changes in the intensity of the reflected beam. The controller generates a control signal for use in aligning the robot with the cell based on a known relationship between the target location determined and the location of the cell.
The present invention also relates to a system for use in a data storage library having a plurality of cells for housing media cartridges, each cell having a location in the library, the library further having a moveable robot for use in retrieving the cartridges from the cells. The system comprises a target in the library. The target has a first target portion in a first plane, and a second target portion in a second plane different than the first plane. The first target portion has a first section with a first reflectivity and a second section with a second reflectivity. The second target portion has a third section with a third reflectivity. In addition, the system comprises a source on the robot for directing a beam toward the target and an actuator for use in scanning the beam source over the first, second and third sections of the first and second target portions. The beam reflects off the sections as a reflected beam. Furthermore, the system comprises a sensor on the robot for sensing the reflected beam and generating a signal representing the intensity of the reflected beam. Finally, the system comprises a controller for receiving the signal from the sensor. The controller determines a location of the target in the library relative to the gripper based on changes in the intensity of the reflected beam. The controller generates a control signal for use in aligning the gripper with the cell based on a known relationship between the target location determined and the location of the cell.
The present invention further relates to a method for use in a data storage library having a plurality of cells for housing media cartridges, each cell having a location in the library, the library further having a moveable robot for use in retrieving the cartridges from the cells. The method comprises providing a target in the library. The target has a first target portion with a first reflectivity, a second target portion with a second reflectivity, and a third target portion with a third reflectivity. In addition, the method comprises providing a source on the robot for directing a beam toward the first, second and third target portions. The beam reflects off the target portions as a reflected beam having an intensity based on the reflectivity of the respective target portion. Furthermore, the method comprises providing a sensor on the robot for sensing the reflected beam and generating a signal representing the intensity of the reflected beam. Finally, the method comprises providing a controller for receiving the signal from the sensor, determining a location of the target in the library relative to the robot based on changes in the intensity of the reflected beam, and generating a control signal for use in aligning the robot with the cell based on a known relationship between the target location determined and the location of the cell.
The present invention still further relates to a method for use in a data storage library having a plurality of cells for housing media cartridges, each cell having a location in the library, the library further having a moveable robot for use in retrieving the cartridges from the cells. The method comprises providing a target in the library. The target has a first target portion in a first plane, and a second target portion in a second plane different than the first plane. The first target portion has a first section with a first reflectivity and a second section with a second reflectivity. The second target portion has a third section with a third reflectivity. In addition, the method comprises providing a beam source on the robot for directing a beam toward the first, second and third sections of the first and second target portions. The beam reflects off the sections as a reflected beam. Furthermore, the method comprises providing a sensor on the robot for sensing the reflected beam and generating a signal representing the intensity of the reflected beam. Finally, the method comprises providing a controller for receiving the signal from the sensor, determining a location of the target in the library relative to the robot based on changes in the intensity of the reflected beam, and generating a control signal for use in aligning the robot with the cells based on a known relationship between the target location determined and the location of the cells.